As you can tell, not my favorite subject. :grumpy: I was going along fine just tinkering with these things and working them out until I started trying to balance this one: Ca3(PO4) + H2SO4 -> CaSO4 + H3PO4 The coefficients I have tried so far are: 2Ca3(PO4) + 3H2SO4 -> 6CaSO4 + 2H3PO4 so on LHS I have 6 Ca, 2 P, 20 O, 6 H, 3 S and on RHS I have 6 Ca, 2 P, 32 O, 6 H, 6 S (I think.. ) I wasn't sure if I needed to keep going and trying different or larger coefficients or if I have already gone wrong somewhere. Also, if anyone has any tips for balancing these things I'd be glad to hear them. My teacher didn't give any formal procedures for working with these. Thanks.